Thermostat.



M. BUTTS. THERMOSTAT. APPLICATION FILED MAY I6. 1914.

Patnted Dec. 26, 1916.

Y 2/ 197m fiflld ATTORNEY'/ WITNESSES UNITED STATES MILLABD BUTTS, OF NEW YORK, Y., INTERTYPE CORPORATION, A

ASSIGNOR, IBY MESNE ASSIGNMENTS, TO CORPORATION OF NEW YORK.

THERMOSTAT.

Specification of Letters Patent.

Patented Dec. 26, 1916.

Application filed May 18, 1914. Serial No. 839,152.

To all whom it may concern:

Be it .known that I, MILLARD Burrs, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented new and useful Improvements in Thermostats, of which the following is a specification.

The present invention relates to improvements in thermostats and more especially to those of the type adapted to regulate the flow of gas or fuel in fluid form to gas burners.

The primary object of the invention is to provide a thermostat of improved construction which is simple and elficient, which is capable of being easily adjusted, and when adjusted will closely and accurately regulate the flow of fuel to maintain the desired temperature ,the jconstruction and relation of the parts being such that strain, due to the relative expansion of the elements, is avoided.

To these and other ends, the invention consists in certain improvements, and com binations and arrangements of parts, all as will be hereinafter more fully described, the novel features being pointed out particula rly in the claims at the end of the specification.

In the accompanying drawingz-Figure 1 represents a vertical section through a thermostat constructed in accordance with the present invention; Fig. 2 is a side elevation of the thermostat with the cover of the valve chamber removed; Fig. 3 is a perspective view of the valve chamber with the cover removed; Fig. 4 is a perspective view of the valve; Fig. 5 is a perspective view of the removable cover plate for the valve chamber.

Similar parts are desi nated by the same reference characters in t e several views.

In the accompanying drawing and in the present specification, I show and describe the invention as embodied in a thermostat adapted to be used in connection with crucibles for melting lead ortype metal for type casting and similar machines, the thermostat serving to.regulate the operation of the gas burners which heat and melt the metal 1n order to'maintain the-metal at the desired temperature. It will be understood, however, that the invention is not restricted to the precise construction shown, as equivalent constructions within the scope of the claims at the end of this specificatioie 1am contemplated and will be included theil'i'wi In the present instance 1 designates head of the thermostat which formsavttlfve chamber, this valve chamber being preferably' provided with a removable did or cover 2 to permit access to the valve chamber, the'removable cover being adapted to fit tightly against the casing and may be removably secured thereto by screws or equivalent means. An inlet pipe 3 admits gas or fuel to the interior of the valve chamber from the source of gas supply, and an outlet pipe 4 conducts the gas from the valve chamber to the burner, the burner not being shown in the present instance, as the construction and mode of operation thereof are well understood in the art. A tube or sleeve 5 is rigidly secured at its upperQcnd to the valve casing 1, the interior of the tubecommunicating with the valve chamber, and a plug 6 is fitted into the lower end of the tube or sleeve 5 and closes the same. A pin 7 is fitted tightly in the plug 6 and serves as an abutment for the lower end of a rod or member 8, the lower end of the latter being on pad or recessed to receive the upper end of the pin 7 which latter may be pointed. The tube or sleeve 5 is composed of a metal or material having a. relatively high co-efiicient of expansion while the rod ,8 is composed of a material having a very low co-eflicient of expansion. In using the thermostat in connection with the metal pots of type castin machines, the thermostat is laced in suc1 a manner that the tube or s eeve 5 is immersed in the molten metal in the crucible. The relative expansion and contraction of the tube or sleeve 5, due to decrease in the temperature of the molten metal, is utilized to regulate the amount of gas passing to the burner through the pipe 4. In the present instance a va ve 9 is employed which is contained in the valve casmg 1 and is adapted to cooperate with one side thereof asa seat to regulate the amount of gas entering the valve chamber by the pipe 3. The valve has a'lug 9 projectin laterally therefrom and the upper end 0 the rod or member 8 engages the under side of'this lug, the upper end of the rod 8 being preferably rounded and seated in a correspondingly shaped recess in the lug 9' to retain; these parts in cofiperative" relathe interior 011 an increase or 5 tion. A. spring 10 normally operates on the valve 9 to move it toward closed position. An adjusting device, preferably a screw ll, is fitted into the valve casing and bears on the valve at a point offset to one side of the point of engagement of the rod 5 with the valve. By setting this screw in different positions the thermostat can be adjusted to maintain any desired temperature. In order to facilitate adjustment of the valve. a pointer let is attached to the head of the screw l1 exteriorly of the valve easing and cooperates with a suitably graduated scale, shown in Fig. 3. In order to cause the flow of gas to respond more quickly to relatively slight movements of the valve 9, a groove 1'12 is preferably formed in that side of the valve casing against which the valve seats, this groove communicating with theinlrt pipe 3. It is also preferable to provide a relatively small pussage 13 between the groove 12 and the pipe lleading; to the burner whereby a small amount of gas may continue to {low to the burner and the b prevent total ei1tingnishing thereof, even though the valve be entirely closed.

The thermostat is preferably adjusted by immersing it in the molten metal in the crurilile or metal pot, the screw 11 being brought down to open the valve until the proper temperature of the metal is reached, whereupon the screw is raised until the llame in the burner is reduced to the point where it will maintain the desired temperature. lhcrear'ter. the thermostat regulates the flow of gas automatically, according to the temperature of the metal, by expansion of the tube or sleeve 5 relatively to the substantially inespansible rod or member, expansion of the tube or sleeve j causing the valve to open. and contraction of the tube or sleeve 5 causing the valve to close. As the expansible' member embodying the tube 5 is adapted to be immersed in the metal, the temperature of which is to be regulatechthis exp-.msihle member will be directly influenced by any variations in the temperature of the metal and will respond at once to such variationswhile the relatively inexpansihle rod or member 8 has a chamber between it and the inclosing tube or sleeve 5 which permits gas to iiow between the members and thereby maintain the rod or member 8 at a L'fillPlll t' lllhl l' lower temperature than the tube or sleeve 5. Moreover, the relation of the "ulvo to the expansible and substantially intxpausihle members is such that strain is avoided upon the occurrence of temperature variations.

I claim as my invention l. The combination of a valve casing having an inlet and an outlet, a valve seat iln-oun'h which the i1:".-t passes, a groove be ing formed within and surrounded by the valve seat and communicating with the. inlet, said groove having a greater discharge area than shid inlet, and relatively expansible members connected to said casing and valve, respectively.

2. A valve casing having an inlet and an outlet, a single unattached member having a spring operative thereon to cover said inlet. aud an adjustable abutment against which said member is fulcrumed loosely, said member being controlled to regulate the opening of the inlet by expansion and contraction of the casing.

3. In a-thermostat for regulating the flow of gas to a burner, the combination with a hollow casing through which the gas flows and provided with an interior valve'sc'at, a valve adapted to coiipcrate with said valve seat and having a spring acting to move it toward said seat, a projection a aiust which said valve abuts loosely as a ulcrumi: the valve having a transverse projecting flange, and a movable rod unattached to but abutting against said flange and actuated by expansion and contraction of a part of the cusing.

at. The combination of a valve casing hav ing an inlet and an outlet both located at the same side thereof and formed with a. valve seat'common to said inlet and outlet, a valve cooperative with said valve seat, and relatively expansible members connected to said casing and valve respectively.

The combination of a valve easing having an inlet and an outlet, a valve seat for said inlet formed with a groove communicating with said inlet, a valve cooperative with said valve seat and operative to cover and uncover said groove, and relatively expansible members connected to said casing and valve, respectively.

6. he combination of a. valve easing ha'vling, an inlet and an outlet in one side thereof, said side of the casing being formed with a valve seat having a groove therein communicating with said inlet, and a passage leading from said groove to said outlet, a valve 00- operative with said valve seat and relatively expansible members connected to said casing and valve respectively.

7. In a thermostat for regulating the flow of gas to a burner, the combination of an upright casing having a gas inlet port toward the lower portion-of the casing and a. gas outlet port the casing. a valve seat being provided for one of said ports, a single valve member having a portion to coiiperate with said seat, an abutment against which said member rests loosely as a fulcrum, controlled means having a loose abutting engagement with said valve member for effecting movements thereof.

8. In a thermostat for controlling the flow of gas to a burner, the combination of a 130 toward the upper portion of and thermostatically valve casing having a heat-controlled expanmhle purtmn, a substantlally non-expanslble member, a valve havlng an unattached Contact with said non-expansiblc 5 mvmbm', an abutment against Wlnch sald valve loosely engages as a fulcrum, and a spring actmg on the valve to close it.

I n testimony whereof I have hereunto set my hand In presence of two subscrlblng w1t- THOMAS S. HOMANS, H. MODERY. 

